Many existing off highway truck payload measurement systems calculate payload weight by measuring the truck's four suspension strut pressures, and use a combination of formulas and empirical data to calculate the payload weight. For instance, co-owned U.S. Pat. No. 5,182,712 to Kyrtsos et al. teaches a dynamic payload monitor with the capability of measuring the compression condition of the truck's four struts while the truck is in motion, in order to produce an even more accurate measurement than that likely possible when the truck is in a stationary position. These strut pressure strategies can typically produce payload weight accuracies on the order of plus or minus 3-5%. While strut pressures provide a fairly good representation of the truck's weight, other factors such as strut seal friction and strut rod bending can reduce the accuracy of the payload measurement system. In addition, the suspension struts support most of the weight of the truck, and therefore, the sensors must be sized large enough to measure the truck weight plus the payload weight. The required large measuring range of the sensors can also tend to reduce the accuracy of the system. Thus, there remains room for improving the accuracy of measuring the payload weight of a dump truck.
The present invention is directed to one or more of the problems set forth above, and to improving accuracy in dump truck payload weight measurements.